Laser surgical probes deliver laser energy from a laser source to a treatment site for tissue. Typically, a laser surgical probe includes a handpiece and an optical fiber that is connected to the laser source by a fiber connector for the probe, so that the optical fiber carries laser energy from the source to the handpiece. For safety reasons, laser sources are configured so that the laser source does not produce laser energy unless a probe is connected to the laser source. Early laser sources used well-known internal circuitry for electrical detection of the probe. Such circuits included, for example, a voltage source coupled to a fixed resistance that would produce a current when a probe connector was connected to the laser source to complete an electrical circuit. When a probe was not connected, the circuit would be open (infinite resistance), and the laser source would be disabled.
U.S. Pat. No. 5,085,492 to Kelsoe et al. (hereinafter “the '492 patent”) discloses an alternative to the internal circuitry for detecting connection of the probe. In the configuration described in the '492 patent, the laser source includes a cantilevered, U-shaped ground wire and a contact that serve as a complementary connector for the fiber connector. The fiber connector in turn includes a network of electrical components establishing a fixed electrical characteristic between a contact element mechanically supported by a fiber holding means and another part of the fiber connector that electrically and mechanically engages with the U-shaped ground wire. This provides a defined electrical characteristic for the fiber connector itself, which is in turned used by the laser source to detect the presence of a connected fiber.
One significant drawback of the system described in the '492 patent is that the laser source can only be used with fiber connectors that include a network of electrical components to define an electrical characteristic for the fiber connector. Modifying the fiber connectors of other laser surgical probes to include such a network of electrical components would introduce additional complications in manufacturing the probe as well as additional cost. There is a need, therefore, for a system that would allow these other laser surgical probes to be used with laser sources like the one described in the '492 patent.